We propose the installation of a computer/computer graphics system for application in structure/function studies of biological macromolecules and molecular biology. The system will consist of a core minicomputer, connected to terminals in Offices and Laboratories, to the x-ray crystallographic data collection facility, and to a color graphics workstation. (Requested items underlined) The system will provide computing and graphics facilities for research projects in the following areas: molecular dynamics simulations of hydration and structure of proteins; X-ray crystallographic structure determination of macromolecules; molecular genetics (nucleic acid and protein sequence determination and comparison; analysis of secondary structure in RNA) studies of enzyme mechanisms (DNA repair system; inhibition of enzymes by transition state analogs; aminoacylation of t-RNA; inhibition of thrombin) biophysical studies (calcium release by sarcoplasmic reticulum; proteins of the hemostatic mechanism).